ISLAMABAD, Pakistan, Feb. 2 -- Pakistani police began hunting Monday for the kidnappers of John Solecki, the American U.N. official who was abducted in the southern Pakistani city of Quetta.

Gunmen kidnapped Solecki, the chief of the U.N. refugee office in Quetta, and fatally shot his driver early Monday in an incident that marked the latest in a series of high-profile kidnappings and targeted hits on foreigners in recent months in the country.

An unknown number of gunmen ambushed Solecki's car in Baluchistan province about 8:30 a.m., soon after he left home for his office, local police officials said. The car's driver, Hashim Raza, was killed almost instantly after the gunmen opened fire on the vehicle, said Khalid Masood, a senior police official in the city.

Few details were immediately available about the U.N. official, but Pakistani authorities said Solecki has worked for the U.N. High Commissioner for Refugees office in Quetta for about two years.

Amena Kamaal, a spokeswoman for the United Nations in the Pakistani capital of Islamabad, confirmed that a foreign U.N. official who has worked for the organization since early 2007 was abducted in Quetta on Monday. But Kamaal said she was unable to release details about the official's background or the incident pending notification of the man's family.

Lou Fintor, a spokesman for the U.S. Embassy in Islamabad, said the embassy was aware of the incident but could not comment further.

The kidnapping in Quetta, a city long considered to be the seat of operations for top al-Qaeda and Taliban commanders, underscored growing concerns about the deteriorating security situation in Pakistan as U.N. Secretary General Ban Ki-moon prepared this week to visit the country.

Poor security, endemic poverty and mounting concerns about hundreds of thousands of Pakistanis displaced by recent violence in the country's North-West Frontier Province and troubled tribal areas will likely be at the top of Ban's agenda. He is scheduled to meet with Pakistani President Asif Ali Zardari and Prime Minister Yousaf Raza Gillani on Thursday. Ban is also scheduled to visit India, where tensions remain high with Pakistan over the investigation of the attacks in the Indian city of Mumbai in November.

Abductions and assassinations of foreigners and aid workers have increased in Pakistan in the past year, affecting the operations of several major humanitarian organizations in the country, including the United Nations. In April, Taliban gunmen kidnapped and later released two local workers with the U.N.'s World Food Program in northwest Pakistan.

Reports of kidnappings of Westerners are rare. The last high-profile abduction of an American was in January 2002, when Wall Street Journal reporter Daniel Pearl was kidnapped and later beheaded. In August, Lynne Tracy, the top U.S. diplomat in the northwest region, narrowly survived an attack on her vehicle in Peshawar by suspected insurgents. In November, gunmen shot and killed American aid worker Stephen Vance in the same city.

No group has asserted responsibility for Solecki's kidnapping, nor have any demands surfaced publicly for his release. Such information generally takes days if not weeks to emerge.

The April abduction of the two aid workers in Pakistan's northwest marked the start of a spate of kidnappings near the Pakistani city of Peshawar, which has been roiled by violence for nearly two years as conditions in neighboring Afghanistan worsened. In November, gunmen kidnapped an Iranian diplomat in the city a day after suspected Taliban insurgents fatally shot Vance.

Last fall, the United Nations ordered its staff in Pakistan to send their families back to their home countries amid heightened security concerns following the September bombing of the Marriott Hotel in Islamabad. That bombing killed at least 50 people, wounded scores and prompted officials at the United Nations and several other diplomatic missions in Islamabad to overhaul their security procedures.

Kamaal said the latest incident in Quetta had again raised alarms about working in Pakistan. But she said it was unlikely to result in a halt to U.N. operations in the country.

"I don't think there's any question that our work will continue because it is badly needed, but there certainly is likely to be discussion about beefing up security," Kamaal said.